EX13-EG-000170 - Exchange messages with a blank sender field must be filtered.

Information

By performing filtering at the perimeter, up to 90 percent of spam, malware, and other undesirable messages are eliminated from the message stream rather than admitting them into the mail server environment. Anonymous email (messages with blank sender fields) cannot be replied to. Messages formatted in this way may be attempting to hide their true origin to avoid responses or to spam any receiver with impunity while hiding their source of origination.

Rather than spend resources and risk infection while evaluating them, it is recommended that these messages be filtered immediately upon receipt and not forwarded to end users.

Solution

Open the Exchange Management Shell and enter the following command:

Set-SenderFilterConfig -BlankSenderBlockingEnabled $true

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_MS_Exchange_2013_Y21M12_STIG.zip

Item Details

Category: SYSTEM AND INFORMATION INTEGRITY

References: 800-53|SI-8(2), CAT|II, CCI|CCI-001308, Rule-ID|SV-84485r2_rule, STIG-ID|EX13-EG-000170, Vuln-ID|V-69863

Plugin: Windows

Control ID: dc2f064829f2277f064091959edb052be0ced4ead7fb2fb871faac91f6d1cc31